On android-arm, GDBserver might insert breaks at wrong addresses.
Feedback on this welcome.

Other configurations and toolchains might work, but haven't been tested.
Feedback is welcome.

Toolchain:

For arm32, x86 and mips32 you need the android-ndk-r6 native
development kit. r6b and r7 give a non-completely-working build;
see http://code.google.com/p/android/issues/detail?id=23203
For the android emulator, the versions needed and how to install
them are described in README.android_emulator.

You can get android-ndk-r6 from
http://dl.google.com/android/ndk/android-ndk-r6-linux-x86.tar.bz2

For arm64 (aarch64) you need the android-ndk-r10c NDK, from
http://dl.google.com/android/ndk/android-ndk-r10c-linux-x86_64.bin

Install the NDK somewhere. Doesn't matter where. Then:

# Modify this (obviously). Note, this "export" command is only done
# so as to reduce the amount of typing required. None of the commands
# below read it as part of their operation.
#
export NDKROOT=/path/to/android-ndk-r<version>

# Do configuration stuff. Don't mess with the --prefix in the
# configure command below, even if you think it's wrong.
# You may need to set the --with-tmpdir path to something
# different if /sdcard doesn't work on the device -- this is
# a known cause of difficulties.

# The below re-generates configure, Makefiles, ...
# This is not needed if you start from a release tarball.
./autogen.sh

# At the end of the configure run, a few lines of details
# are printed. Make sure that you see these two lines:
#
# For ARM:
# Platform variant: android
# Primary -DVGPV string: -DVGPV_arm_linux_android=1
#
# For x86:
# Platform variant: android
# Primary -DVGPV string: -DVGPV_x86_linux_android=1
#
# For mips32:
# Platform variant: android
# Primary -DVGPV string: -DVGPV_mips32_linux_android=1
#
# For ARM64 (AArch64):
# Platform variant: android
# Primary -DVGPV string: -DVGPV_arm64_linux_android=1
#
# If you see anything else at this point, something is wrong, and
# either the build will fail, or will succeed but you'll get something
# which won't work.

# Build, and park the install tree in `pwd`/Inst
#
make -j4
make -j4 install DESTDIR=`pwd`/Inst

# To get the install tree onto the device:
# (I don't know why it's not "adb push Inst /data/local", but this
# formulation does appear to put the result in /data/local/Inst.)
#
adb push Inst /

# To run (on the device). There are two things you need to consider:
#
# (1) if you are running on the Android emulator, Valgrind may crash
# at startup. This is because the emulator (for ARM) may not be
# simulating a hardware TLS register. To get around this, run
# Valgrind with:
# --kernel-variant=android-no-hw-tls
#
# (2) if you are running a real device, you need to tell Valgrind
# what GPU it has, so Valgrind knows how to handle custom GPU
# ioctls. You can choose one of the following:
# --kernel-variant=android-gpu-sgx5xx # PowerVR SGX 5XX series
# --kernel-variant=android-gpu-adreno3xx # Qualcomm Adreno 3XX series
# If you don't choose one, the program will still run, but Memcheck
# may report false errors after the program performs GPU-specific ioctls.
#
# Anyway: to run on the device:
#
/data/local/Inst/bin/valgrind [kernel variant args] [the usual args etc]

# One common cause of runs failing at startup is the inability of
# Valgrind to find a suitable temporary directory. On the device,
# there doesn't seem to be any one location which we always have
# permission to write to. The instructions above use /sdcard. If
# that doesn't work for you, and you're Valgrinding one specific
# application which is already installed, you could try using its
# temporary directory, in /data/data, for example
# /data/data/org.mozilla.firefox_beta.
#
# Using /system/bin/logcat on the device is helpful for diagnosing
# these kinds of problems.